Summary:
This patch addresses, for the interfaces implemented by `COFFDump.cpp`,
multiple issues identified with the current structure of
`llvm-objdump.h` in the review of D72973.
This patch moves implementation details of the tool into an
`llvm::objdump` namespace for external linkage names, splits the
implementation details into separate headers for each implementation
file, and uses qualified names when declaring members of the
`llvm::objdump` namespace in place of leaving the namespace definition
open.
Reviewers: jhenderson, DiggerLin, jasonliu, daltenty, MaskRay
Reviewed By: jhenderson, MaskRay
Subscribers: MaskRay, rupprecht, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77285
Hubert Tong